Safety device for gas drums



Aug. 7, 1923n W. J. TRAXEL SAFETY DEVICE FOR GAS DRUMS Filed Nov. 1'1, 1920 H64 was4 29W Q Patented Aug. 7, i923.

WILLLSJKE JAMES Tt-AXEL, OF CHICAGO, ILLINOIS.

SAFETY DEVCE :FOR GASDRUMS.

Application filed November 11, 1920. Serial No. 23,261.

To @ZZ whom t may concer/rt Be it known ythat l, WILLIAM Janne rfnAXnL, afcitizen of the United States, residing at Chicago,I county of Cook, and

State of Illinois, have invented certain new and useful improvements inSafety evices forGas Drums, of which the following` is a specification. v

The gas drums'with which this invention is particularly concerned are ordinarily heavy steel tubes completely closed at one end and closedfat the othei'end except that provision is made for the introduction and exhaustion of thecompressed gas. These drums are ordinarily used for storage and transportation of compressed gases jsuch as oxygen and hydrogen. The gases are commonly forced into kthe drums by a pump under very high pressure until the vdrums are fully charged. It not infrequently happenstthat such drums when charged with gas are exposed to temperatures which raise the pressure above the safety point, and -where no precautions have been taken to the contrary explosions have occurred which endanger the lives of the operators and the property adjacent the exploded drum. It

.iscommon practice, therefore,l to provide ,means for releasing thegas when the pressure which the drum may safely withstand is exceeded, and the device most generally used for 'this purpose is a metal disk inter- `posed in the connection between the interior of the drum and an outlet to the atmosphere, the disk being of such strength as to withstand pressures which may safely be carried by the drum but to yield and rupture when such pressures are exceeded, permitting the contents of the drum to escape to the atmosphere.

Experience has shown that from some cause heretofore unknown these disks weaken after a comparatively short life averaging only a small number of refillings of the drum and rupture before the danger point is reached, thus releasing the contents of the drum which become a total loss to the owner. A large percentage of gas handled in these drums is lost in this manner. Frequently the disks yield during storage or transportation, sometimes without any apparent immediate cause and under normal conditions, and in other instances under somewhat abnormal conditions such as relatively small increases in temperature which would. not endanger the drum or cause the tion had noty been applied thereto except disk to burst if the latter were in proper condition. I have discovered that the weakening of the disks, which are commonly of bronze, is caused by a weakening of the 50 metal crystals of which the disk is composed, due to fatigue caused by flexings of the disk during the filling operation due to the pulsating action of the pump. At each stroke of the pump the ldisk Vis momentarily pressed or bulged outward, returning between strokes to substantially a plane condition. This alternate pressure and relief fieXes the disk at a circumference adjacent the edge thereof, alternately stressine' and relieving the metal fibres and crystais so that the latter are slowly weakened and broken thus reducing the strength of the disk along the line of such circumference. Vhen, therefore, the disk is subjected to any abnormal pressure, even well within that at which it was designed to break, it4 yields and ruptures withthe result referred to above. y

My invention is based upon this discovery of the reason for the heretofore mysterious reakage of these safety disks and consists in providing means for so supportingv the disk during the filling operation as to relieve it of the stress and strainy otherwise imposed upon it by the pulsating action of the filling pump. After the filling is com pleted the support is removed and the drum is then in the same condition as if my inventhat the safety disk retains its original Y strength.

Referring to the drawing Fig'. l is a transverse vertical axial section through a drum in condition for filling with my invention applied thereto; Fig. 2 a similar view after the filling is completed and the device embodying my invention removed; Fig. 3 a side elevation of a detail of the preferred form of device embodying my invention, and Figs. 4i and 5 side and end elevations respectively of a detail.

In the drawing I have shown the tube 6 and the filling head 7 thereof as of cone ventional form7 the latter comprising a threaded end 8 screwed into the drum, a nipple 9 for connection to the pump or compressoiand a screw valve l0 cooperating with the seat 1l for preventing the escape of gas after the filling is completed. The 110 filling head 7 is as usual further formed with a nipple 12 for the safety device, said nipple havingl a passage 13 communicating with the charging-passage of the filling head. The

nipple 12 is exteriorly threaded and receives `an interior threaded union or annulus 111 which has an inwardly projecting annular y flange 15 intermediate the threaded portion 16 which screws upon a nipple and a reduced witlreachtstroke of'tlieicompresser a pulsa-V A designed.

'for shipment or storage,

threaded portion 17. In theusual construction to which my invention is applied Vthe safety disk 18 is clamped between the flange 15 and the end of thenipple, a fiber washer A plug 2O is not emdevicev when ready to close the outer end of the cap or section, but a passage to "the air is provided at 21 which, when the 19 packing the joint. Y ployed commonly in my satet disk isrru Jtured` Qermitsthe esca e y v l indicated above, and, as in the device ashere- Y toforeconstructed the'diaphragm must sustain these'pulsations unsupported, it ultimately weakens under the intermittent ileX ture until `it is no longer able to withstand the pressureY for which it was designed and bursts under4 a pressure which may be far below that yfor which 'theV diaphragm was By my invention l support the diaphragm during the charging. operation' by aljsolid abutment sot-hat it is not subjected to fleX- turer by the' pulsations of the pump and therefore' theiiber's'and crystals thereof re- Y tain their original strength andthelife of the diskl is almost indefinitely prolonged.

Obviously, the specific means for supporting the disk may vary widely. My preierred means for the purpose, as illustrated in Figs. 1 and 3, is a screw plug 22 fitting the thread 17 in the safety cap and having an extension 23 of such diameter and length as to extend through thefinternal flange of the safety cap and bear evenly against the safety disk when the enlarged threaded portion of the plug seats against the flange 1,5.` Preferably, the length of the extension k23 is not such as to materially bend or displace theV safety disk. For convenience of opera.

tion a hand wheel 24 is applied to the outer end ofV the plug 22. It will now be seen that Y by removing the plug 2O and rep-lacing it by thecharging plug 22 prior to the filling operation the diaphragm is rig-idly sup- Y ported against the pulsations of the Vpump and therefore its fiber and crystals are not stretched, tensed 'or weakened during the filling operation. lVhen the filling .is completed, the filling plug is removed r'and lthe plug 20 substituted therefor, which plug does not support the diaphragm and permitsit yto yield and rupture under-dangerous pressures and permit the gas in thecontainer to escape through the opening 21.

VI claim:V Y Y 1. A gas drum comprising a container proper and a. filling head, a'nipple'on the filling head, a union onv the nipple, a safety disc the edge of which Yis'clampsdbe'tween the nipple and the union,VV and a plug screwed into the union and engaging' the safety disc. Y 2. A gas drum comprising a container and a filling head, a nipple on the/filling head having a passage communicating with the interior ofthe drum, a safety cap on said nipple having an interior flange, safetydisk intermediate Vsaid flange and 'Y nipple,

said cap being threaded beyond theL flange, a threaded plug screwed intothesafetyeip and having Ya projection besiiingy 'upon the safety disk and means forti-iriiir'ig saidvplug.

`VVILLIillVI JAMESTRAXEL. 

